1/*	$NetBSD: if_dl.h,v 1.18 2005/12/11 23:05:24 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)if_dl.h	8.1 (Berkeley) 6/10/93
32 */
33
34/*
35 * A Link-Level Sockaddr may specify the interface in one of two
36 * ways: either by means of a system-provided index number (computed
37 * anew and possibly differently on every reboot), or by a human-readable
38 * string such as "il0" (for managerial convenience).
39 *
40 * Census taking actions, such as something akin to SIOCGCONF would return
41 * both the index and the human name.
42 *
43 * High volume transactions (such as giving a link-level ``from'' address
44 * in a recvfrom or recvmsg call) may be likely only to provide the indexed
45 * form, (which requires fewer copy operations and less space).
46 *
47 * The form and interpretation  of the link-level address is purely a matter
48 * of convention between the device driver and its consumers; however, it is
49 * expected that all drivers for an interface of a given if_type will agree.
50 */
51
52#ifndef _NET_IF_DL_H_
53#define _NET_IF_DL_H_
54
55#include <sys/socket.h>
56
57/*
58 * Structure of a Link-Level sockaddr:
59 */
60struct sockaddr_dl {
61	u_char	    sdl_len;	/* Total length of sockaddr */
62	sa_family_t sdl_family;	/* AF_LINK */
63	u_int16_t   sdl_index;	/* if != 0, system given index for interface */
64	u_char	    sdl_type;	/* interface type */
65	u_char	    sdl_nlen;	/* interface name length, no trailing 0 reqd. */
66	u_char	    sdl_alen;	/* link level address length */
67	u_char	    sdl_slen;	/* link layer selector length */
68	char	    sdl_data[12]; /* minimum work area, can be larger;
69				     contains both if name and ll address */
70};
71
72/* We do arithmetic directly with these, so keep them char instead of void */
73#define LLADDR(s) ((char *)((s)->sdl_data + (s)->sdl_nlen))
74#define CLLADDR(s) ((const char *)((s)->sdl_data + (s)->sdl_nlen))
75
76#ifndef _KERNEL
77
78#include <sys/cdefs.h>
79
80__BEGIN_DECLS
81void	link_addr(const char *, struct sockaddr_dl *);
82char	*link_ntoa(const struct sockaddr_dl *);
83__END_DECLS
84
85#endif /* !_KERNEL */
86
87#endif /* !_NET_IF_DL_H_ */
88